passing values in Generic methods

Hello I am reading a book on C# and on the generic methods section I got this question: How are object values passed in generic methods? a. They are passed by value. b. They are passed by reference. c. They must be encapsulated in a property. d. They are passed during class instantiation. the correct answer in the book is B, but after I do some checking I can verify that I can pass values by ref or without ref. so what can I be missing here? static void Main(string[] args) { int iX = 1; int iY = 2; testig1<int>(ref iX, ref iY); testig2<int>(iX, iY); } public static void testig1<T>(ref T valueX, ref T ValueY) { } public static void testig2<T>(T valueX, T ValueY) { } with an object, I still don't need to use ref keywork... maybe I making some confusion about the "reference" they are refering to. The code above and here is mine from testing. class testObj { public int test; } static void Main(string[] args) { testObj test = new testObj(); test.test = 0; testig2<testObj>(test, test); } public static void testig2<T>(T valueX, T ValueY) { valueX = ValueY; } can you show me a sample code to explain that the awser B is the correct? regards.